Adapter assembly for interconnecting electromechanical surgical devices and surgical loading units, and surgical systems thereof

ABSTRACT

The present disclosure relates to an adapter assembly for electrically and mechanically interconnecting electromechanical surgical devices and surgical loading units. The adapter assembly includes an articulation assembly having a rotatable drive shaft having a proximal end rotatable by a surgical device and a distal end having a gear with external teeth, a gear nut including external gear teeth meshingly engaged with the external teeth of the gear, a screw disposed within the gear nut and including external threads engaged with internal threads of the gear nut such that the screw is axially moveable relative to the gear nut, and an articulation bar operably coupled to the screw such that axial movement of the screw results in corresponding axial movement of the articulation bar.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 62/259,351 filed Nov. 24, 2015, the entire disclosure of which is incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to adapter assemblies for use in surgical systems. More specifically, the present disclosure relates to adapter assemblies for use with, and to electrically and mechanically interconnect, electromechanical surgical devices and surgical loading units.

BACKGROUND

A number of surgical device manufacturers have developed product lines with proprietary powered drive systems for operating and/or manipulating a surgical device. In many instances the surgical devices include a powered handle assembly, which is reusable, and a disposable end effector or the like that is selectively connected to the powered handle assembly prior to use and then disconnected from the end effector following use in order to be disposed of or in some instances, sterilized for re-use.

Many of the existing end effectors for use with many of the existing powered surgical devices and/or handle assemblies are driven by a linear force. For examples, end effectors for performing endo-gastrointestinal anastomosis procedures, end-to-end anastomosis procedures and transverse anastomosis procedures, each typically require a linear driving force in order to be operated. As such, these end effectors are not compatible with surgical devices and/or handle assemblies that use a rotary motion to deliver power or the like.

In order to make the linear driven end effectors compatible with powered surgical devices and/or handle assemblies that use a rotary motion to deliver power, adapters and/or adapter assemblies are used to interface between and interconnect the linear driven end effectors with the powered rotary driven surgical devices and/or handle assemblies. For example, a plurality of rotary motion to linear motion converting assemblies may extend through an adapter to effect different functions of an end effector. Components of these assemblies, however, may require more input torque to generate a linear force if, for example, the assemblies include a gear assembly having a low gear ratio and/or the output force is not axial to the load.

Accordingly, a need exists for an adapter for a powered rotary driven surgical device that requires less rotary motor torque to generate a linear force.

SUMMARY

According to one embodiment of the present disclosure, an adapter assembly for selectively interconnecting a surgical loading unit and a surgical device is provided. The adapter assembly includes: an adapter housing configured to connect to a surgical device; an outer tube having a proximal end supported by the adapter housing and a distal end configured to connect to a surgical loading unit; and a transmission assembly at least partially disposed within the adapter housing. The transmission assembly includes: a proximal rotation receiving member connectable to a drive shaft of a surgical device; a distal force transmitting member connectable to an axially translatable drive member of a surgical loading unit; at least one pin securely disposed within the adapter housing; and a bearing assembly coupled to the proximal rotation receiving member and the distal force transmitting member. The bearing assembly is axially movable along the at least one pin in response to rotational motion of the proximal rotation receiving member thereby axially moving the distal force transmitting member.

According to a further embodiment of the present disclosure, an electromechanical surgical system is provided. The electromechanical surgical system includes a surgical loading unit including a proximal body portion and a tool portion, and an axially translatable drive member; a surgical device including a device housing and at least one rotatable drive shaft supported in the device housing; and an adapter assembly configured to selectively interconnect the surgical loading and the surgical device. The adapter assembly includes an adapter housing configured to connect to the surgical device; an outer tube having a proximal end supported by the adapter housing and a distal end configured to connect to the surgical loading unit; and a transmission assembly at least partially disposed within the adapter housing. The transmission assembly includes: a proximal rotation receiving member connectable to the rotatable drive shaft of the surgical device; a distal force transmitting member connectable to the axially translatable drive member of the loading unit; at least one pin securely disposed within the adapter housing; and a bearing assembly coupled to the proximal rotation receiving member and the distal force transmitting member. The bearing assembly is axially movable along the at least one pin in response to rotational motion of the proximal rotation receiving member thereby axially moving the distal force transmitting member.

According to an aspect of any of the above embodiments, the bearing assembly is non-rotatably disposed within the adapter housing. The bearing assembly also includes a bearing housing and a bearing rotatably disposed within the bearing housing.

According to another aspect of any of the above embodiments, the distal force transmitting member is coupled to an inner race of the bearing.

According to a further aspect of any of the above embodiments, the bearing housing further includes a threaded bore threadably coupled to a threaded distal end of the proximal rotation receiving member. The threaded bore includes an insert molded threaded member, which is formed from a polymer selected from the group consisting of fluoropolymers, polystyrenes, and polyaryletherketones.

According to yet another aspect of any of the above embodiments, the at least one pin is coupled to a support ring member disposed within the adapter housing.

According to yet further aspect of any of the above embodiments, the axially translatable drive member is configured to articulate the tool portion of the surgical loading unit.

Further details and aspects of exemplary embodiments of the present disclosure are described in more detail below with reference to the appended figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein:

FIG. 1 is a perspective view of an electromechanical surgical system including a handheld surgical device, an adapter assembly, and a surgical loading unit in accordance with the principles of the present disclosure;

FIG. 2 is a perspective view illustrating a connection of the adapter assembly and the handheld surgical device of the electromechanical surgical system of FIG. 1;

FIG. 3 is a perspective view of the adapter assembly of FIGS. 1 and 2, with most parts separated;

FIG. 4 is a cross-sectional view of the adapter assembly of FIGS. 1-3, taken along section line “4-4” of FIG. 1;

FIG. 5 is a cross-sectional view of the adapter assembly of FIGS. 1-4, taken along section line “5-5” of FIG. 1;

FIG. 6 is a perspective view, with parts removed, of an outer housing of the adapter assembly of FIGS. 1-5; and

FIG. 7 is a perspective view, with parts separated, of the surgical loading unit of FIG. 1.

DETAILED DESCRIPTION

Electromechanical surgical systems of the present disclosure include surgical devices in the form of powered handheld electromechanical instruments configured for selective attachment to a plurality of different end effectors that are each configured for actuation and manipulation by the powered handheld electromechanical surgical instrument. In particular, the presently described electromechanical surgical systems include adapter assemblies that interconnect the powered handheld electromechanical surgical instruments to the plurality of different end effectors. Each adapter assembly includes a firing assembly, an articulation assembly, and a rotation assembly that is operatively coupled to a powered handheld electromechanical surgical instrument for effectuating actuation and/or manipulation of the plurality of different end effectors.

Embodiments of the presently disclosed electromechanical surgical systems, surgical devices/handle assemblies, adapter assemblies, and/or loading units are described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein the term “distal” refers to that portion of the system, assembly, device, and/or component thereof, farther from the user, while the term “proximal” refers to that portion of the system, assembly, device, and/or component thereof, closer to the user.

Turning now to FIG. 1, an electromechanical surgical system, in accordance with the present disclosure, generally referred to as 10, includes a surgical device 100 in the form of a powered handheld electromechanical instrument, an adapter assembly 200, and a surgical loading unit 300 (e.g., an end effector, multiple- or single-use loading unit). Surgical device 100 is configured for selective connection with adapter assembly 200, and, in turn, adapter assembly 200 is configured for selective connection with surgical loading unit 300. Together, surgical device 100 and adapter assembly 200 may cooperate to actuate surgical loading unit 300.

Surgical device 100 includes a handle housing 102 including a circuit board (not shown) and a drive mechanism (not shown) situated therein. The circuit board is configured to control the various operations of surgical device 100. Handle housing 102 defines a cavity therein (not shown) for selective removable receipt of a rechargeable battery (not shown) therein. The battery is configured to supply power to any of the electrical components of surgical device 100. Handle housing 102 supports a plurality of motors (not shown), each in electrical communication with the circuit board and each including a rotatable drive shaft extending therefrom.

Handle housing 102 includes an upper housing portion 102 a which houses various components of surgical device 100, and a lower hand grip portion 102 b extending from upper housing portion 102 a. Lower hand grip portion 102 b may be disposed distally of a proximal-most end of upper housing portion 102 a. The location of lower housing portion 102 b relative to upper housing portion 102 a is selected to balance a weight of a surgical device 100 that is connected to or supporting adapter assembly 200 and/or surgical loading unit 300.

Handle housing 102 provides a housing in which the drive mechanism (not shown) is situated. The drive mechanism is configured to drive shafts and/or gear components in order to perform the various operations of surgical device 100. In particular, the drive mechanism is configured to drive shafts and/or gear components in order to selectively articulate surgical loading unit 300 about a central longitudinal axis “X” and relative to a distal end of adapter assembly 200, to selectively rotate surgical loading unit 300 about longitudinal axis “X” and relative to handle housing 102, to selectively move/approximate/separate an anvil assembly 306 and a cartridge assembly 308 of surgical loading unit 300 relative to one another, and/or to fire a stapling and cutting cartridge within cartridge assembly 308 of surgical loading unit 300.

As shown in FIG. 2, in conjunction with FIG. 1, handle housing 102 of surgical device 100 defines a connection portion 104 configured to accept a proximal end of adapter assembly 200. Connection portion 104 houses an electrical pass-through connector 105 in electrical communication with the circuit board (not shown) and a plurality of rotatable drive shafts or connectors 106. Each rotatable drive connector of the plurality of rotatable drive connectors 106 can be independently, and/or dependently, actuatable and rotatable by the drive mechanism or motors (not shown) housed within housing handle 102. In embodiments, the plurality of rotatable drive connectors 106 includes first, second, and third rotatable drive connectors, 106 a, 106 b, and 106 c arranged in a common plane or line with one another. As can be appreciated, the plurality of rotatable drive connectors 106 can be arranged in any suitable configuration. The drive mechanism (not shown) may be configured to selectively drive one of the rotatable drive connectors 106 of surgical instrument 100, at a given time.

Handle housing 102 supports a plurality of finger-actuated control buttons, rocker devices, and the like for activating various functions of surgical device 100. For example, handle housing 102 supports a plurality of actuators including, for example, an actuation pad 108 to effectuate, for example, opening, closing, and/or firing of surgical loading unit 300. Handle housing 102 can support actuators 109 a, 109 b which can be disposed in electrical communication with the motors of handle housing 102 to effectuate, for example, rotation of first, second, and/or third rotatable drive connectors 106 a, 106 b, and/or 106 c for actuation thereof to enable adjustment of one or more of the components of adapter assembly 200. Any of the presently described actuators can have any suitable configuration (e.g., button, knob, toggle, slide, etc.).

Reference may be made to International Application No. PCT/US2008/077249, filed Sep. 22, 2008 (Inter. Pub. No. WO 2009/039506), and U.S. Patent Application Publication No. 2011/0121049, filed on Nov. 20, 2009, the entire contents of each of which being incorporated herein by reference, for a detailed description of various internal components of and operation of exemplary electromechanical surgical systems, the components of which are combinable and/or interchangeable with one or more components of electromechanical surgical systems 10 described herein.

With reference to FIGS. 1-3, adapter assembly 200 includes an outer housing 202 and an outer tube 204 that extends distally from outer housing 202 to a distal cap 206 thereof along central longitudinal axis “X.” Outer housing 202 and outer tube 204 are configured and dimensioned to house the components of adapter assembly 200. Outer housing 202 of adapter assembly 200 includes a proximal housing 202 a and a distal housing 202 b. Proximal housing 202 a defines a cavity 203 a therein and has a distal lip 203 b extending radially outwardly therefrom. Distal housing 202 b includes a first half-section 208 a and a second half-section 208 b that are configured and adapted to mate together. Each of first and second half-sections 208 a and 208 b defines an internal lip receiving annular recess 209 a adapted to receive a portion of distal lip 203 b of proximal housing 202 a to facilitate securement of proximal and distal housings 202 a and 202 b. Each of first and second half-sections 208 a and 208 b defines an articulation-assembly-receiving recess 209 b that is in communication with an outer-tube-receiving channel 209 c. Each outer-tube-receiving channel 209 c is defined through a distal end of one of first and second half-sections 208 a and 208 b.

A mounting assembly 210 is supported on proximal housing 202 a of outer housing 202 for attachment/detachment of the adapter assembly 200 to surgical device 100. Mounting assembly 210 includes a shaft 212 that extends outwardly from proximal housing 202 a, a spring 214 that is supported about an outer surface of shaft 212, and a mounting button 216 that engages spring 214 and shaft 212. Spring 214 contacts a bottom surface of mounting button 216 to bias mounting button 216 upwardly to an extended position spaced from proximal housing 202 a. Spring 214 is sufficiently compressible to enable mounting button 216 to be depressed downwardly from the extended position to a compressed position. In the compressed position, mounting button 216 is disposed in close approximation with proximal housing 202 a and offset from the extended position. Mounting button 216 includes sloped engagement features 216 a that are configured to contact connection portion 104 (FIG. 1) of handle housing 102 while mounting button 216 is in the extended position to facilitate securement of proximal housing 202 a to connection portion 104 of handle housing 102.

Proximal housing 202 a of outer housing 202 rotatably supports first, second and third connector sleeves 220, 222, and 224, respectively, arranged in a common plane or line with one another. Each of the first, second, and third connector sleeves 220, 222, and 224 is configured to mate with respective first, second and third rotatable drive connectors 106 a, 106 b, and 106 c of surgical device 100.

Adapter assembly 200 also includes a first, a second, and a third biasing member 226, 228, and 230 disposed distally of respective first, second and third connector sleeves 220, 222, and 224. First, second, and third biasing members 226, 228, and 230 act on respective first, second, and third connector sleeves 220, 222, and 224 to help maintain engagement of first, second, and third connector sleeves 220, 222, and 224 with the distal end of respective first, second, and third rotatable drive connectors 106 a, 106 b, and 106 c of surgical device 100 when adapter assembly 200 is connected to surgical device 100. First, second, and third biasing members 226, 228, and 230 contact or rest against a plate bushing 232 disposed within proximal housing 202 a, and function to bias respective first, second, and third connector sleeves 220, 222, and 224 in a proximal direction.

Plate bushing 232 is secured to an inner housing 234 of adapter assembly 200. The plate bushing 232 and inner housing 234 each define a plurality of apertures (not explicitly shown) that are arranged in the common plane or line of first, second, and third connector sleeves 220, 222, and 224 for rotatably supporting a first rotatable drive shaft 242, a second rotatable drive shaft 252, and a third rotatable drive shaft 272, respectively, of first, second, and third force/rotation transmitting/converting assemblies 240, 250, and 270 (FIG. 4) disposed within outer housing 202 and outer tube 204 of adapter assembly 200. Each of the first, second, and third connector sleeves 220, 222, and 224 is configured to mate with a proximal end of respective first, second, and third rotatable drive shafts 242, 252, and 272, and each of the first, second, and third rotatable drive shafts 242, 252, and 272 functions as a rotation receiving member to receive rotational forces from respective first, second, and third rotatable drive connectors 106 a, 106 b, and 106 c of surgical device 100.

Each of the force/rotation transmitting/converting assemblies 240, 250, and 270 is configured and adapted to transmit/convert a speed/force of rotation (e.g., increase or decrease) of first, second and third rotatable drive connectors 106 a, 106 b, and 106 c of surgical device 100 into axial translation and/or rotation of components of force/rotation transmitting/converting assemblies 240, 250, and 270 to effectuate a function of surgical loading unit 300, as described in greater detail below.

As shown in FIGS. 3-5, first force/rotation transmitting/converting assembly or drive assembly 240 of adapter assembly 200 includes first rotatable drive shaft 242 which, as described above, is rotatably supported within outer housing 202. First rotatable drive shaft 242 includes a proximal portion 242 a having a non-circular or shaped proximal end 242 b configured for connection with first connector sleeve 220 which is connected to respective first rotatable drive connector 106 a of surgical device 100 (FIG. 2), and a distal portion 242 c having a threaded outer profile or surface. A housing bearing member 218, such as a thrust bearing, receives and supports proximal portion 242 a of first rotatable drive shaft 242 to enable first rotatable drive shaft 242 to rotate.

First force/rotation transmitting/converting assembly 240 further includes a drive coupling nut 244 rotatably coupled to threaded distal portion 242 c of first rotatable drive shaft 242, and which is slidably disposed within a center tube 205 that is at least partially disposed within both outer housing 202 and outer tube 204, and concentric with central longitudinal axis “X.” Drive coupling nut 244 is slidably keyed with center tube 205 so as to be prevented from rotating as first rotatable drive shaft 242 is rotated. In this manner, as first rotatable drive shaft 242 is rotated, drive coupling nut 244 is translated along threaded distal end portion 242 c of first rotatable proximal drive shaft 242 and, in turn, through/along outer tube 204.

First force/rotation transmitting/converting assembly 240 further includes a distal drive member 246 that is mechanically engaged with drive coupling nut 244, such that axial movement of drive coupling nut 244 results in a corresponding amount of axial movement of distal drive member 246. Distal end portion 246 a of distal drive member 246 supports a connection member 248 configured and dimensioned for selective engagement with a drive member 324 of drive assembly 320 of surgical loading unit 300 (FIG. 7). Drive coupling nut 244 and/or distal drive member 246 function as a force transmitting member to components of surgical loading unit 300.

In operation, as first rotatable drive shaft 242 is rotated, due to a rotation of first connector sleeve 220, as a result of the rotation of first rotatable drive connector 106 a of surgical device 100, drive coupling nut 244 is caused to translate axially along threaded distal end portion 242 c of first rotatable drive shaft 242, which in turn, causes distal drive member 246 to translate axially relative to outer tube 204. As distal drive member 246 is translated axially, with connection member 248 connected thereto and engaged with drive member 324 of drive assembly 320 of surgical loading unit 300, distal drive member 246 causes concomitant axial translation of drive member 324 of surgical loading unit 300 to effectuate opening or closing of a tool assembly 304 and/or a firing of tool assembly 304 of surgical loading unit 300 (FIG. 7).

A lock mechanism 236 is supported on the distal housing 202 b for fixing the axial position and radial orientation of distal drive member 246. Lock mechanism 236 includes a button 236 a slidably supported on distal housing 202 b of outer housing 202 of adapter assembly 200. Button 236 a is connected to an actuation bar 236 b that extends longitudinally through outer tube 204. Actuation bar 236 b moves upon movement of button 236 a. Button 236 a is configured to be moved from a distal position to a proximal position to lock or prevent distal drive member 246 from distal and/or proximal movement, and from a proximal position to a distal position to allow unimpeded axial translation and radial movement of distal drive member 246.

In operation, in order to lock the position and/or orientation of distal drive member 246, a user moves button 236 a of lock mechanism 236 from a distal position to a proximal position, thereby causing a lock out (not shown) to move proximally such that a distal face of the lock out moves out of contact with a camming member 238, which causes camming member 238 to cam into recess 246 b of distal drive member 246. In this manner, distal drive member 246 is prevented from distal and/or proximal movement. When button 2364 a of lock mechanism 236 is moved from the proximal position to the distal position, actuation bar 236 b moves distally into the lock out (not shown), against the bias of a biasing member (not shown), to force the camming member 238 out of recess 246 b of distal drive member 246, thereby allowing unimpeded axial translation and radial movement of distal drive member 246.

With reference to FIGS. 3-6, second force/rotation transmitting/converting assembly or articulation assembly 250 of adapter assembly 200 includes second drive shaft 252 rotatably supported within outer housing 202. Second rotatable drive shaft 252 includes a non-circular or shaped proximal end 252 a configured for connection with second connector sleeve 222 which is connected to respective second rotatable drive connector 106 b of surgical device 100 (FIG. 2). Second rotatable drive shaft 252 further includes a gear 254 including a plurality of external teeth 254 a, such as a spur gear, keyed to, or integrally formed on, a distal end 252 b thereof.

Articulation assembly 250 further includes a gear nut 256 rotatably coupled to gear 254 of second rotatable drive shaft 252. Gear nut 256 is rotatably disposed within distal housing 202 b of outer housing 202 and is concentric with central longitudinal axis “X.” Gear nut 256 includes a cylindrical body 258 having external gear teeth 260 extending from and disposed around an external surface 258 a of cylindrical body 258 and internal threads 262 extending along an internal surface 258 b of cylindrical body 258. External teeth 254 a of gear 254 of second rotatable drive shaft 252 meshingly engages external gear teeth 260 of gear nut 256 such that rotation of second rotatable drive shaft 252 results in rotation of cylindrical body 258 of gear nut 256.

A screw 264 is disposed within cylindrical body 258, and includes external threads 264 a that are engaged with internal threads 262 of cylindrical body 258. Screw 264 is slidably keyed to a stationary sleeve 207 by hub 265 that, in turn, is keyed to center tube 205 so that screw 264 is preventing from rotating as cylindrical body 258 of gear nut 256 is rotated. In this manner, as gear nut 256 is rotated, screw 264 is axially translated along internal surface 258 b of cylindrical body 258 of gear nut 256 along central longitudinal axis “X.” An articulation bearing 266, such as a radial/thrust bearing, is disposed within an internal surface 264 b of screw 264 and includes an inner race 266 a that is independently rotatable relative to an outer race 266 b.

Second drive converter assembly 250 of adapter assembly 200 further includes an articulation bar 268 having a proximal portion 268 a secured to inner race 266 a of articulation bearing 266, such as by coupler 267, so that articulation bar 268 is both longitudinally translatable during axial movement of screw 264 and rotatable about center tube 205 during rotation of adapter assembly 200 and surgical loading unit 300. A distal portion 268 b of articulation bar 268 includes a slot 268 c therein, which is configured to accept a flag of the articulation link 330 (FIG. 7) of surgical loading unit 300. Articulation bar 268 functions as a force transmitting member to components of surgical loading unit 300. It is envisioned that articulation bearing 266 allows for free, unimpeded rotational movement of surgical loading unit 300 when its anvil and cartridge assemblies 306 and 308 (FIG. 7) are in an approximated position and/or when anvil and cartridge assemblies 306 and 308 are articulated.

In operation, as second proximal drive shaft 252 is rotated due to a rotation of second connector sleeve 222, as a result of the rotation of the second rotatable drive connector 106 b of surgical device 100, gear nut 256 is caused to be rotated about center shaft 205. Rotation of gear nut 256, in turn, causes screw 264 to be axially translated along internal threads 262 of cylindrical body 258 of gear nut 256, which in turn causes articulation bar 268 to be axially translated relative to outer tube 204. As articulation bar 268 is translated axially, articulation bar 268, being coupled to articulation link 330 of surgical loading unit 300, causes concomitant axial translation of articulation link 330 of surgical loading unit 300 to effectuate an articulation of tool assembly 304 of surgical loading unit 300 (FIG. 7). Articulation bar 268, being secured to inner race 266 a of articulation bearing 266, is free to rotate about central longitudinal axis “X” relative to outer race 266 b of articulation bearing 266.

As illustrated in FIGS. 3-5, third force/rotation transmitting/converting assembly or rotation assembly 270 of adapter assembly 200 includes third rotatable drive shaft 272 rotatably supported within outer housing 202. Third rotatable drive shaft 272 includes a non-circular or shaped proximal end 272 a configured for connection with third connector sleeve 224 which is connected to respective third rotatable drive connector 106 c of surgical device 100 (FIG. 2). Third rotatable drive shaft 272 includes a spur gear 274 keyed to, or integrally formed, on a distal end 272 b thereof.

Rotation assembly 270 includes a two-piece rotation ring gear 276 fixedly supported in and connected to distal housing 202 b of outer housing 202 of adapter assembly 200. Rotation ring gear 276 defines an internal array of gear teeth 276 a. Rotation ring gear 276 includes a pair of diametrically opposed, radially extending protrusions 276 b projecting from an outer edge thereof. Protrusions 276 b are disposed within recesses 201 defined in distal housing 202 b, such that rotation of rotation ring gear 276 results in rotation of distal housing 202 b, and vice a versa. A reversing spur gear 278 inter-engages spur gear 274 of third rotatable drive shaft 272 to the internal array of gear teeth 276 a of rotation ring gear 276.

In operation, as third rotatable drive shaft 272 is rotated, due to a rotation of third connector sleeve 224, as a result of the rotation of the third rotatable drive connector 106 c of surgical device 100, spur gear 274 of third rotatable drive shaft 272 engages reversing spur gear 278 causing reversing spur gear 278 to rotate. As reversing spur gear 278 rotates, rotation ring gear 276 also rotates thereby causing outer housing 202 to rotate. As outer housing 202 is rotated, outer tube 204 is caused to be rotated about central longitudinal axis “X” of adapter assembly 200. As outer tube 204 is rotated, surgical loading unit 300, which is connected to distal cap 206 of adapter assembly 200, is also caused to be rotated about central longitudinal axis “X” of adapter assembly 200.

With reference to FIGS. 3 and 5, adapter assembly 200 includes an electrical assembly 280 supported on and in outer housing 202. Electrical assembly 280 includes a plurality of electrical contact blades 282, supported on a circuit board 284, for electrical connection to electrical pass-through connector 105 of surgical device 100 (FIG. 2). Electrical assembly 280 serves to allow for calibration and communication of life-cycle information to the circuit board of surgical device 100.

Electrical assembly 280 further includes a strain gauge 286 electrically connected to circuit board 284. First rotatable drive shaft 242 extends through strain gauge 286, which provides a closed-loop feedback to a firing/clamping load exhibited by first rotatable drive shaft 242.

Electrical assembly 280 also includes a slip ring 288 non-rotatably and slidably disposed along drive coupling nut 244. Slip ring 288 is in electrical connection with circuit board 284 and functions to permit rotation of first rotatable drive shaft 242 and axial translation of drive coupling nut 244 while still maintaining electrical contact thereof with at least another electrical component within adapter assembly 200, and while permitting the other electrical components to rotate about first rotatable drive shaft 242 and drive coupling nut 244.

Turning now to FIGS. 1 and 7, an embodiment of a surgical loading unit 300 is shown. Surgical loading unit 300 includes a proximal body portion 302 and a tool assembly 304. Proximal body portion 302 is releasably attached to distal cap 206 of adapter assembly 200, and tool assembly 304 is pivotally attached to a distal end of proximal body portion 302. Tool assembly 304 includes an anvil assembly 306 and a cartridge assembly 308. Cartridge assembly 308 is pivotal in relation to anvil assembly 306 and is movable between an open or unclamped position and a closed or clamped position. Proximal body portion 302 includes at least a drive assembly 320 and an articulation link 330.

Drive assembly 320 includes a flexible drive beam 322 having a distal end 322 a and a proximal engagement section 322 b. A proximal end of proximal engagement section 322 b includes diametrically opposed inwardly extending fingers 322 c that engage a hollow drive member 324 to fixedly secure drive member 324 to the proximal end of drive beam 322. Drive member 324 receives connection member 248 of distal drive member 246 of drive assembly 240 of adapter assembly 200 when surgical loading unit 300 is attached to distal cap 206 of adapter assembly 200.

Cartridge assembly 308 of tool assembly 404 includes a staple cartridge 310 removably supported in a carrier 312. Staple cartridge 310 defines a central longitudinal slot 310 a, and a plurality of linear rows of staple retention slots 310 b positioned on each side of the central longitudinal slot 310 a. Each of the staple retention slots 310 b receives a single staple 314 and a portion of a staple pusher 316. During operation of surgical device 100, drive assembly 320 abuts an actuation sled 318 and pushes actuation sled 318 through the staple cartridge 310. As the actuation sled 318 moves through staple cartridge 310, cam wedges of the actuation sled 318 sequentially engage staple pushers 316 to move staple pushers 316 vertically within staple retention slots 310 b and sequentially eject a single staple 314 therefrom for formation against an anvil plate 306 a of anvil assembly 306.

Proximal body portion 302 of surgical loading unit 300 includes an articulation link 330 having a hooked proximal end 330 a which extends from a proximal end of surgical loading unit 300 which is received in slot 268 c of distal portion 268 b of articulation bar 268 of articulation assembly 250 when surgical loading unit 300 is attached to distal cap 206 of adapter assembly 200. Articulation link 330 has a distal end 330 b pivotably secured to tool assembly 304.

Persons skilled in the art will understand that the structures and methods specifically described herein and shown in the accompanying figures are non-limiting exemplary embodiments, and that the description, disclosure, and figures should be construed merely as exemplary of particular embodiments. It is to be understood, therefore, that the present disclosure is not limited to the precise embodiments described, and that various other changes and modifications may be effected by one skilled in the art without departing from the scope or spirit of the disclosure. Additionally, the elements and features shown or described in connection with certain embodiments may be combined with the elements and features of certain other embodiments without departing from the scope of the present disclosure, and that such modifications and variations are also included within the scope of the present disclosure. Accordingly, the subject matter of the present disclosure is not limited by what has been particularly shown and described. 

What is claimed is:
 1. An adapter assembly for selectively interconnecting a surgical loading unit and a surgical device, the adapter assembly comprising: an adapter housing configured to connect to a surgical device; an outer tube having a proximal end supported by the adapter housing and a distal end configured to connect to a surgical loading unit; a gear connectable to a drive shaft of the surgical device; an axially translatable screw connectable to the gear; an articulation bar connectable to the axially translatable screw; a center shaft securedly disposed within the adapter housing, the axially translatable screw positioned around the center shaft; and an articulation bearing coupled to the axially translatable screw and the articulation bar, the articulation bearing being axially movable along the center shaft in response to rotational motion of the gear thereby axially moving the articulation bar.
 2. The adapter assembly according to claim 1, wherein the articulation bearing is coupled to an inner surface of the axially translatable screw.
 3. The adapter assembly according to claim 1, further comprising a stationary sleeve disposed about the center shaft, the stationary sleeve defining a channel, wherein the axially translatable screw includes a hub positioned in the channel.
 4. The adapter assembly according to claim 1, wherein the articulation bearing is rotatably disposed within the axially translatable screw.
 5. The adapter assembly according to claim 4, wherein the articulation bar is coupled to an inner surface of the articulation bearing.
 6. The adapter assembly according to claim 4, wherein the axially translatable screw is threaded and the axially translatable screw is coupled to a threaded distal end of the gear.
 7. The adapter assembly according to claim 6, wherein the axially translatable screw includes an insert molded threaded member.
 8. The adapter assembly according to claim 7, wherein the insert molded threaded member is formed from a polymer selected from the group consisting of fluoropolymers, polystyrenes, and polyaryletherketones.
 9. The adapter assembly according to claim 1, wherein the center shaft is coupled to the adapter housing.
 10. An electromechanical surgical system, comprising: a surgical device including a device housing and a rotatable drive shaft supported in the device housing; a surgical loading unit including a surgical tool; and an adapter assembly configured to selectively interconnect the surgical loading unit and the surgical device, the adapter assembly including: an adapter housing configured to connect to the surgical device; an outer tube having a proximal end supported by the adapter housing and a distal end configured to connect to the surgical loading unit; a gear connectable to the rotatable drive shaft of the surgical device; an axially translatable screw connectable to the gear; an articulation bar connectable to the axially translatable screw; a center shaft securedly disposed within the device housing of the surgical device, the axially translatable screw positioned around the center shaft; and an articulation bearing coupled to the axially translatable screw and the articulation bar, the articulation bearing being axially movable along the center shaft in response to rotational motion of the gear thereby axially moving the articulation bar.
 11. The electromechanical surgical system according to claim 10, wherein the axially translatable screw is configured to articulate the surgical tool.
 12. The electromechanical surgical system according to claim 10, wherein the articulation bearing is rotatably disposed within the axially translatable screw.
 13. The electromechanical surgical system according to claim 12, wherein the articulation bar is coupled to an inner surface of the articulation bearing.
 14. The electromechanical surgical system according to claim 12, wherein the axially translatable screw is threaded and the axially translatable screw is coupled to a threaded distal end of the gear.
 15. The electromechanical surgical system according to claim 14, wherein the axially translatable screw includes an insert molded threaded member.
 16. The electromechanical surgical system according to claim 15, wherein the insert molded threaded member is formed from a polymer selected from the group consisting of fluoropolymers, polystyrenes, and polyaryletherketones.
 17. The electromechanical surgical system according to claim 10, wherein the center shaft is coupled to the adapter housing.
 18. The electromechanical surgical system according to claim 10, further comprising a stationary sleeve disposed about the center shaft, the stationary sleeve defining a channel, wherein the axially translatable screw includes a hub positioned in the channel. 